Impulse clock



Jan. 3, 1933. s l 1,892,710

IMPULSE CLOCK Filed Aug. 16, 1930 m3 %7'7ze c Patented Jan. 3, 1933 UNITED STATES PATENT OFFICE ROY F. SMITH, OF EL PASO, TEXAS, ASSIGNOR OI ONE-HALF TO FRED xrrcnnns, or EL raso, 'rnxas IMPULSE CLOCK Application filed August 18, 1930. Serial No. 475,818.

In electric clock systems of the type in which impulses are transmitted at regular 1ntervals (such as once per minute) to a plural ity of secondary clocks which have electromagnets or other means for advancing the clock-trains one step for each impulse, 1t is generally known that the secondary clocks sometimes get out of step with the master clock and various schemes have been devised to correct the secondary clock at regular intervals (say once per hour). One scheme for effecting this result consists in provldmg a stop for physically obstructing each clocktrain at regular intervals (say once per hour if the clock is fast, with means for automat1- cally removing the stop on the hour so that the clock-train may resume its advance after 1t has been retarded the required amount. In order to correct slow secondaries it has been so proposed to transmit a series of fast impulses just before the end of the hour rapidly to advance the secondaries until the stops obstruct further advance, further movement of the clock-trains being permitted by automatic re- 26 moval of the stops at the end of the hour.

None of these schemes have been entirely satisfactory, an outstanding objection consisting in that the ratchet or other means moving back and forth to advance the clocktrain creates an objectionable noise after the clock-train has been obstructed by the aforesaid stop due to the fact that the back-andforth movement continues after the stop becomes effective and inasmuch as the clocktrain can not be advanced by the ratchets the latter noisily pound against the stationary ratchet wheel. The objects of the present invention are to prevent the aforesaid chattering and generally to improve the construction and operation of secondary clocks of the impulse type.

For the purpose of illustrating the genus of this invention a typical embodiment is 4 shown in the accompanying drawing in which Fig. 1 is a rear view of the clock mechanism, parts being broken away;

Fig. 2 is a similar View showing the parts in a different position;

Fig. 3 is a top plan view of the mechanism;

Fig. 4 is a rear elevation of the stop and associated weight;

Fig. 5 is a circuit diagram illustrating one method of operation and Fig. 6 is a similar circuit diagram illustrat ing another wiring arrangement.

The particular embodiment of the invention shown for the purpose of illustration comprises two ratchet wheels 1 and 2 with associated pawls 3 and 4. The ratchet wheels 1 and 2, which are fastened together and to the shaft 5, have their teeth facing in opposite directions; the ratchet 3 turns the wheels in a clockwise direction while the pawl 4 holds the' wheels against retrograde movement while the pawl 3 is being retracted. The pawl 3 is carried on an arm 6 pivoted at 7 arm 6 being provided with a stop 8 engageable with the teeth of wheel 1 to present overthrow by pawl 3. The pawl 3 is retracted by a magnet 9 operative upon armature 10 fast to arm 6 and after the magnet is deenergized the pawl is again advanced by spring 11. All of these parts are standard equipment and the novel parts which constitute the illustrative embodiment of the present invention will now be described.

A ring 12, of metal or other material having appreciable weight, is slidably mounted on the rear face of the ratchet'wheel 1 by means of two pins 13 and 13 extending axially from the wheel through slots 14 and 14 in the ring with heads on their outer ends to retain the ring. The pins 13 and 13' are so located that the ring may slide back and forth throughout a limited range along the diameter of the wheel extending through the pins. Fast to the ring near the slot 14 is a stop 15 which extends outwardly beyond the outer periphery of the ring and ratchet wheel 1 and then hooks forwardly a'distance sufficient to overhang the stop 8 in one of the sixty positions of the ratchet wheel and ring. The stop 15 is so adjusted that when the closed end of slot 14 rests upon the pin 13 the overhanging portion 16 of the stop is in close juxtaposition to the upper surface of the stop 8 so that the pawl 13 can not be lifted an appreciable distance without also lifting the weight 12 (Fig. 2). In order to lift the stop 15 so that it will pas to a position over the stop 8 in one of the sixty steps of the mechanism durin each cycle, a pin 17 is mounted on the wei ted ring 12 to engage a stationary cam 1 As the stop 15 approaches the stop 8 the cam 18 acting on the pin 17 gradually moves the stop 15 farther awa from the axis of the shaft 5 and when t e stop 15 reaches a position over the stop 8 the pin 17 drops ofi the toe 19 of the cam 18 thereby.

rmitting the overhanging portion 16 of t e stop 15 to drop into close juxtaposition to the stop 8.

A second pin 17' similar to pin 17 may if desired be provided at a point on the ring approximately op osite the location of the pin 17 to prevent t e center of gravity of the weighted ring from shifting to the left of the vertical plane of the shaft 5 during the first half of each cyclic movement of the parts inasmuch as such a shift of the center gravity might cause the ratchet wheel to overthrow. (Obviously no such tendency exists as long as the center ravity of the weighted ring is to the right 0% the agtion of the shaft 5.)

The operation of the clock is as follows: If the clock is fastthe stop 15 will lock the arm 6 in the position shown in Fig. 1 before the end of the hour (according to the master clock) and the clock will remain stationary until the end of the hour. During this stationary period the pawl 3 and associated parts can not chatter back and forth because held by the stop 15. If the clock is slow it is brought to the stop position by a series of ally obstructing said back-andforth move fast impulses transmitted to the magnet 9 by the master clock just before the end of the hour. Means for transmitting such impulses are disclosed in the Keilien applications Serial Nos. 341,17 6 and 341,177 filed Februairy 19, 1929 and is'not here re roduced as it is unnecessary for a clear un erstanding of the present invention. Advance of the clocktrain is resumed at the end of the hour by transmitting to the magnet 9 an impulse of sufiiciently increased ma 'tude to lift the weighted ring 12. A suitable arran ment for transmittin such an impulse is a so disclosed in the a oresaid Keilien applications. Inasmuch'as a single impulse of increased magnitude moves the overhanging portion 16 of the stop 15 beyond the stop 8 only a single impulse of increased magnitude is requiredpnce per hour (or other predetermined interval). Obviously the increased force ap plied to the arm 6 to lift the weighted ring may be produced in a great many ways as for example by increasing the current to the single winding of magnet 9 or providin two windin on magnet 9, only one of which is utilize in normally advanci the clock and both of which are utilized ad 'tively in prodii cing )the impulse of increased magnitude ig. 6 etc.

It should be understood that the present disclosure is for the purpose of illustration onl and that this invention includes all m ifications and equivalents which fall within the scope of the appended claims.

I claim:

1. A secondary clock having a clock-train and comprising driving means movable back and fort for advancing the clock-train step bystepinresponsetoimpulsesfrom amaster clock, and resetting means in the clock for automatically rendering said'di-i means ineffective at predetermined intervals, said resetting meansincluding a stop for physically obstructing saidback-and-forth movement. A

2. A secondary clock having a clock-train andcom rising driving means movable back and fortii for advancing the clock-train step by step in response to impulses from a master clock; and resetting means in the clock for automatically rende said driving means ineffective at predetermined intervals, said resetting means including a stop for physically obstructing said back-and-forth movement at a predetermined point. in the cyclic movement of the clock-tram. v

-3. A secondary clock having a clock-train and comprising driving means movable back and forth for advancing the-clock-train step by step in response to impulses from a master clock, and resetting means in the clock for automatically rendering said driving means inefiective at predetermined intervals, said resetting means including a stop for physiment, and means responsive to-an from the master clock for removing sai stop after the clock has been reset. g

4. A secondary clock a clock-train and comprising driving means movable back and forth for advancing the clock-train step by step inres nae toimpulses from a master clock, an resetting means in the clock for automatically rendering said driving means ineflective at predetermined intervals, said resettingstmeans including a stop for physically o ructing said back-andiorth movement, and means responsive to an impulse from the master clock for removi said stop after the clock has been reset, sai

last means including a non-polarized electromagnet.

5. A secondary clock having a clock-train and comprising a ratchet for advancing the clock-train step by step in response to impulses from a master'clock, and resetting means in the clock for automatically rendering said ratchet ineifective at predetermined intervals, said resetting means including a step for physicall obstructing backand-forth movement of ratchet.

6. A secondary clock having a clock-train and comprising a ratchet for advancing the clock-tram step bystep in response to impulses from a clock, and

means in the clock for automatically rendering said ratchet ineffective at predetermined intervals, said resetting means including a stop actuated by said ratchet for physically obstructing the back-and-forth movement of the ratchet at a predetermined point in the cycle movement of the clock-train.

7. A secondary clock having a clock-train and comprising a ratchet for advancing the clock-train step by step in response to impulses from a master clock, resetting means in the clock for automatically rendering said ratchet ineffective at predetermined intervals, said resetting means including a stop for physically obstructing the back-and-forth movement of the ratchet, and means responsive to an impulse from the master clock for removing said stop after the clock is reset.

8. A secondary clock having a clock-train and comprising a ratchet for advancing the clock-train step by step in response to impulses from a master clock, resetting means an impulse of increased magnitude, and means for camming' said stop to retracted position as the clock-train approaches said predetermined point and then dropping the stop to holding position when the clock-train reaches said point.

12. A secondary clock comprising a ratchet and ratchet wheel for advancing the clocktrain step by step in response to driving impulses from a master clock, a stop operative at a predetermined oint in each cycle of the clock-train for hol ing the ratchet against retraction by said driving impulses, and means responsive only to other impulses from the master clock for moving the stop from holding position.

Signed by me at El Pas'o, Texas, this 29th day of July, 1930.

ROY F. sum.

in the clock for automatically renderlng said ratchet ineffective at predetermined intervals, said resetting meansincluding a stop for physically obstructing the back-andforth movement of the ratchet, and means responsive to an impulse from the master clock for removing said stop after the clock is reset, said last means including a nonpolarized electromagnet.

9. A secondary clock having a clock-train and comprising a ratchet and ratchet wheel for advancing the clock-train step by step in response to drivingimpulses from a master clock, and a stop operative at a predetermined point in each cycle of the clock-train for holding the ratchet against retraction by normal driving impulses, the stop being movable from holding position by the ratchet in response to an impulse of increased magnitude.

10. A secondary clock having a clock-trainand comprising a ratchet and ratchet wheel for advancing the clock-train step by step in response to driving impulses from a master clock, a weighted stop-mounted on the ratchet Wheel to slide radially in one dimension of the wheel for holding the ratchet against retraction by normal driving impulses at a predetermined point in each cycle of the clocktrain, the stop being movable from holding position by the ratchet in response to an impulse of increased magnitude.

, 11. Secondary clock havin a clock-train and comprising a ratchet an ratchet wheel for advancing the clock-train step by step in response to driving impulses from a master clock, a weighted stop mounted on the ratchet wheel to slide radially in one dimension of the wheel for holding the ratchet against 'retract-ion by normal driving impulses at a predetermined point in each cycle of the clock-train, the stop bein movable from holding position by the rate at in response to 

